I personally have worked with Brian Gavin multiple times and they have a great attention to detail, and they have great finishing skills. With an all metal setting like an x-prong finish and the attention to detail is everything. I used to own one.
Brain Gavin has a lovely X prong, but my favorite is the one they carry by the designer H Levi called the Lattice, they have several versions. And the one I like the best and think is the most elegant, by far, is the Lattice Thin Comfort Shank. Here is the link to that version on the H Levi site: http://www.hlevi.com/s717.html BGD is their authorized representative. Also, here is the 'regular' Lattice by H Levi (I really do prefer the other one though, unless you have a stone larger than 7.25mm) http://www.hlevi.com/s702.html